Basically it takes both a .py and .pyui file and packages them into a single script, which, when run, will extract both files again.

Originally I planned to make the resulting script be the original program with the .pyui file and an extraction process added, though in the end I decided against it to avoid potential incompatibilities and to allow editing of the .pyui file. It would probably be possible to implement this, so if anyone wants to, feel free to use all of or parts of my code.

At the moment, no. It would definetely be possible to implement, though it would require a better UI to select multiple files. If you have more than one or two files to distribute it would probably also be better to set up a GitHub repo. That way updating will also be easier, as you only need to update the files that actually changed.